CAP risk increases in groups with reduced immune resilience and limited pulmonary reserve. Key risk groups include adults aged 65+ and people with chronic lung disease (COPD/asthma), heart disease, diabetes, or chronic kidney disease. Smoking, heavy alcohol use, poor nutrition, and poor oral hygiene can further raise risk. Immunosuppression (cancer therapy, long-term corticosteroids, organ transplant, etc.) increases both incidence and the likelihood of severe outcomes. Crowded living conditions, high exposure settings, and seasonal outbreaks—especially influenza—also amplify risk. Risk stratification informs both prevention priorities (vaccination and lifestyle) and treatment intensity (outpatient vs inpatient management).